The packaging industry today is almost entirely automated. For manufactures of packaged items, an automated packaging process is quicker, less expensive and safer than its manual counterpart.
A typical automated case packaging assembly includes a collator feeder of items to be packaged, a case blank feed device, a case folding device, a case advance section and a compression area. The collator arranges the items to be packaged and transfers them to the folding device. At the same time, a case blank feed device pulls a flat pre-cut case blank from a stack of case blanks and transfers it to the folding device. The blank is set in place and receives the items for packaging. The folding device partially folds the case blank around the items to form the case and transfers the case to the case advance section. The case advance section applies adhesive and provides the final folding to the case. The case then enters the compression section where it is compressed either vertically or horizontally before it is stacked and ready for shipping.
A case blank feed device is designed to contain a plurality of pre-cut case blanks and singularly feed them into a folding device. In the past, case blank feed devices were designed to contain a vertical stack of case blanks where the stack of blanks rested on a series of fixed tabs or lips. A single case blank was transferred by means of a single suction force applied to the underside of the bottom most blank in the stack. The suction force would pull the blank downward far enough to cause the blank to deflect and clear the fixed lips or tabs.
This method and structure have proved to be ineffective. The use of fixed tabs to support a stack of case blanks requires the use of considerable force to remove the bottom blank from the stack. The force must overcome the friction created by the fixed structure coupled with the weight of the stack. As the stack weight increases, the friction increases and thus more force is needed to remove the bottom blank.
In addition to the problems related to the structure of case blank feed devices, previous blank feed removal methods have been found to be ineffective and costly. In the past, a single vacuum force was applied to the underside center of the bottom blank in a stack of blanks contained in a structure having an open bottom. The single application of vacuum force is ineffective because it requires the blank to significantly deflect from the center of the blank. This deflection also requires the blank to travel downward a considerable distance before the blank clears the tabs. The extensive deflection and considerable downward travel by the blank frequently causes the blank to partially clear the fixed lips or tabs which results in jamming the entire process.
Due to the previous blank feed removal methods, prior blank feed devices had to be designed so as to limit the number of blanks in a stack. Because the friction created by the stack weight against the fixed structure is high, the stack weight had to be minimized in order for the vacuum force to effectively remove a blank. Consequently, a smaller stack height required blanks be added to the stack at more frequent intervals. This required manual feeding and additional downtime if the stack was completely depleted before more blanks were added. Closer attention to the blank feed device and more frequent down time resulted in productivity losses for the entire packaging assembly line.
Thus, there is a need for a case blank feed device that is capable of effectively operating with a large stack of case blanks.
There is a further need for a case blank feed device that decreases the friction along the stack support as the bottom case blank is removed from a stack of case blanks.
There is yet a further need for a case blank feed device that more efficiently removes the bottom blank from a stack of blanks.
There is still a further need for a blank feed device that allows for an increased load of case blanks to be contained within the device while maintaining an effective blank removal process.